Speech enhancement using microphone arrays
Darren C. Moore · QUT ePrints (Queensland University of Technology) · 2000
This thesis presents a comparative analysis of baseline microphone array speech enhancement techniques that are prominent in current literature. Delay-sum beamforming, sub-array beamforming, near- and far-field superdirectivity, the generalised sidelobe canceller and the adaptive system for microphone-array noise reduction (AivINOR) are evaluated in varying noise conditions and for different array geometries. The effect of complementing each technique with a postfilter is also assessed. A novel beamformer, termed the near-field adaptive beamformer (NFAB), is introduced and then shown to provide superior enhancement performance over any of the baseline techniques assessed. A description of the design and implementation of a high-speed, multi-channel speech data acquisition system is also presented.